HALFMOON — Students were kept sheltered in classrooms Wednesday afternoon after discovery of a bomb threat written in a room at Mechanicville High School, police and school officials said.

The threat was found at 12:45 p.m, the officials said. The Saratoga County Sheriff's Office was notified immediately, resulting in the recommendation for the "shelter in place" procedure, a school statement said. The sheriff's department called the response a lockdown that lasted about 45 minutes.

Sheriff's officials and a sheriff's explosives detection dog was brought in. Two local ambulance services also responded. No explosives were found and the investigation is continuing.

When the situation was cleared, students went to a modified schedule to accommodate the delay, the school statement said.